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From: neese@adaptx1.UUCP
Newsgroups: comp.periphs.scsi
Subject: Re: <14414@nightowl.MN.ORG>
Message-ID: <283400128@adaptx1>
Date: 29 May 91 15:42:32 GMT
References: <452@hawkmoon.MN.ORG>
Lines: 34
Nf-ID: #R:hawkmoon.MN.ORG:452:adaptx1:283400128:000:1580
Nf-From: adaptx1.UUCP!neese    May 28 15:45:00 1991


>>>The AHA-1540A/1542A user's
>>>manual [(c) 1989] that i have for the 1542a states on page 3-2 that i
>>>must remove the terminators at locations RN3, RN4, and RN5.
>
>>The terminator resistors for the 1542A are located at RN3, RN4, and RN5.
>>The 1542A is a surface mount full length board.  The only removeable parts
>>are the BIOS, firmware, and the resistor terminator packs.
>
>This is what i have.  It is full length and is surface mounted.  It has only
>a few chips that are removable and has a floppy connection.
>
>>>to the board and are labeled RN1, RN3, RN5, and RN6.  They are scattered
>>>at various locations all over the board (RN1 by J1, RN3 by J4, RN5 and
>>>RN6 by the BIOS).  Are the terminators for this board really the two
>>>removable resistor DIPS RN2 and RN4?  If so, why did the board change
>>>the number of packs from 3 to 2 or from 2 to 3 (depending on which came
>>>first; my documentation or my board)?
>
>>Sounds like the 1540 adapter.  This adapter is a TTL based adapters with only
>>one surface mount part (AIC-6250).  The DIPS's are the terminator packs for
>>this adapter.
>
>Hmmm, but isn't the only (logical) difference between the 1540A and the 1542A
>the floppy support?  I have floppy support on my board.

No, the AHA-1540 was the original adapter we did.  It did not have room for
the floppy controller as it was mostly TTL based with one surface mount
chip (AIC-6250).  This board was very crowded.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex
				uunet!cs.utexas.edu!utacfd!merch!adaptex!neese